Farmer's fever. Systemic manifestation of farmer's lung without lung involvement.

A 35-year-old dairy farmer presented with recurrent febrile episodes over more than three years. Fever up to 39 degrees C occurred only if he was in contact with the dairy barn and typically appeared at 4 to 8 h after an otherwise usual barn exposure. He had no dyspnea and throughout this period repeated physical examinations, chest roentgenograms, and lung functions remained normal. He was bronchoscoped and lavaged on three occasions, a lymphocytic alveolitis was always present and once, immediately after an acute episode, an important increase in lavage neutrophils was also found (47 percent). Transbronchial lung biopsy specimens showed a moderate cellular infiltrate but no granuloma or fibrosis. Three other persons who worked at the same farm had no similar manifestations or respiratory illnesses. The patient therefore had typical systemic manifestations of acute farmer's lung, but without the lung involvement required to confirm that diagnosis. Furthermore, his disease does not fit the entities known as grain fever and organic dust toxic syndrome. We believe that this patient presented a different entity that we coined "farmer's fever."